Endless-track base



Dec. 7 ,1926.

F. E. SMITH ENDLESS TRACK BASE 2 Smeets-She@'TM Original Filed Sept. 21,1922 Invezo: Faq/VK E. 5x7/7H,

2 Sheets-Sheet 2 [mentor: faq/VK E 57W/ TH Dec. 7 19,26.

F. E. SMITH I ENDLESS TRACK BASE original Filed sept. 2i, 1922 Iig 4.

Il llll Witnesses: 4

VPatented Dec. 7,4 1926.

UNITED, STATES 1,609,783 PATENT OFFICE.

,FRANK E. SMITH, F SGO'ITDALE, PENNSYLVANIA.

ENDLESS-TRACK BASE.

Original application filed September 21, 1922, Serial No. 589,515.Divided and this application led July 7, 1923. Serial No. 650,013.

Thisk invention relates to endless track bases for use with loadingmachines, cranes or other heavy traveling machines, and while notlimited thereto, relates more particularlyto a base for loading.Amachines adapted to load coal and other mined material within a mine,such as described in my co-pendingapplication, Serial N o. 589,515, led`September 21, 1922, which has resulted in Patent l0 No. 1,466,917,datedSeptember 4, 1923, of

which this application is a division.

One object of this invention is to provide an endless'track baseembodying a threepoint suspensionfor the main frame which l5 may, whendesired, be locked to form a fourpoint suspension.

Another object is to provide a main frame suspension which embodiesanovel form of equalizing mechanism whereby the upward movement of onecrawler will impart a downward movement, of the other crawler.

A further object is to provide an endless track base of this classhaving the novel construction, design and combination of parts 35hereinafterdescribed and illustrated in the accompanying drawings, inwhich- Figure 1 is a sectional plan 'of a base embodying this invention.

Y Figure 2 is a longitudinal vertical section on the line II--II ofFigure 1.

Figure 3 is atransverse vertical section on the lines III-III of Figure1.

Figure 4 is a fragmentary sectional elevat-ion illustrating the brake orlocking device.

4Referring more particularly to the drawings, the numeral 2 designatesthe structural base frame adapted to support the loading mechanism.

Thel base 2 of the machine is provided with endless track crawlerscomprising crawler chains 3 which are trained around drive sprockets 4atone end and idler wheels 5 at the other end. The drive sprockets 4 are45- mounted on a shaft 12, while the idler wheels 5"'a`re mounted onstubshafts 6 journaled in the crawler frames.

Thebase or main frame 2 consists of hollow side girders composed of sideplates 7 and top channel 8, which are tied together by a transverseplate 9 at the bottom, cross girder 10 at the-rear end, shaft 12 andother structural members as are common in the art.

The crawler frames are also of hollow girder construction, and eachconsists of two `ets 4. The sprockets 4 are provide The crawler chains3;.are propelled by means of power applied to the drive s rockbeveledgear faces 18 adapted to be connected to any suitable source of power(not shown) carried by the base. Y

A three-point equalizing suspension for the crawler frames is formed bymounting the crawler frames at their rear ends on the fixed shaft 12 andleaving them free at their forward ends. An equalizing shaft 20 isjournaled in suitable bearings in the main frame or base 2 and isconnected to the crawler frames through pinions 21-21 keyed to theshaft, and meshing with racks or gear segments 22-23, respectively,secured to the crawler frames. The gear segments 22 and 23 are on theopposite sides of their respective pinions 21-21 The load is equallydistributed on each crawler. Therefore, if one crawler is raised higherthan the other, the shaft 2O will be rotated due to the gear and rackconnection with the crawler frame, and thus the other crawler will beforced down a distance Vequal to the amount the first crawler wasraised.

The shaft 20 is provided with brake drums 25 having brake bands 26thereon. which bandsv are adapted to be tightened'on thedrums by screwshafts 26a to lock the shaft 20l against rotation when it is desired toform a four-point suspension for the crawler frames.

From the above, itfwill be readily understood that I have provided anendless track base provided with a novel form of equalizing mechanismthat may readily be rendered inoperative when desired to provide a rigidfour-point suspension.

It will be understood that while I have shown and described one specificembodiment of my invention, I do not wish to be limited thereto, sincevarious modications may be made Without departing from the with scope ofmy invention as defined in the appended claims.

I claim:

l. In a self-propelled land vehicle having an endless track. base, thecombination with a main frame, of a pair of crawler frames, said crawlerframes being pivotally mounted at their rear ends on a ixed shaftmounted in said main frame and having their forward ends movablevertically relative to said main frame, means for automatically causingthe forward ends oi said crawler frames to move in opposite verticaldirection to equalize the load when traveling over an uneven surface,said means comprising an equalizing shaft journaled in suitable bearingsin the main frame, pinions on the opposite ends of said equalizingShaft, gear segments secured to said crawler frame on the opposite sidesoi said pinions and meshing therewith, whereby if one crawler frame israised higher than the other, said equalizing shaft will be rotated dueto said meshed pinions and gear segments and thus force down the othercrawler frame an equal distance.

2 In a self-propelled land vehicle having an endless track base, thecombination with a main frame, of a pair of crawler frames, said crawlerframes being pivotall)T mounted at their rear ends on a fixed shaftmounted in Said main frame and having their forward ends movablevertically relative to said main frame, means for automatically causingthe forward ends of said crawler frames to move in opposite verticaldirection to equalize the load when traveling over an uneven surface,said meanscomprising an equalizing shaft journaled in suitable bearingsin the main frame, pinions on the opposite ends of said equalizingshaft, gear segments secured to said crawler frame on the opposite sidesof said pinions and meshing therewith, whereby if one crawler frame israised higher than the other` said equalizing' shaft will be rotated dueto said meshed pinions and gear segments and thus force down the othercrawler frame an equal distance, and means for locking said equalizingshaft against rotation to form a rigid four-point suspension of the mainframe when desired.

In testimony1 whereof I have hereunto set my hand.

FRANK E. SMITH.

